Centrifugal separator bowl



Janie, 1937.

G. J. sTREz-YNsKl CENTRIFUGAL SEPARATOR BOWL Filed sept. 1e. 1933I @ffml E i Patented Jan. 19, 1937 UNIT-.ED STATES PATENT OFFICE ApplicationSeptember 16, 1933, Serial No. 689,707

13 Claims.

`My Yinvention .relates to centrifugal bowls for the separation of acidsludge from oil .and is particularly adapted for use in cases where a vsmall quantity ofl'free acid separates from both the oil and the sludge.

One object of :the .invention is to provide a centrifugal bowl in whichthe relation between separated oil and sludge will be unaffected bysimultaneous separation of Vsmall quantities of acid heavier than eitherthe oil or the sludge, in which centrifugal force will help to vholdVany removable members in place, and the removable members of which canbe exchanged without disassembly of the bowl. Another object of theinventionis to facilitate the .thorough removal from the bowl, at theconclusion of the separating operation, of heavy matter deposited onAthe bowl wall. y

The invention is particularly well adapted for use inf-self drainingbowls of the type disclosed in my co-pending application, Ser. No.

663,295, led March 29, 1933, now Patent No. 2,000,459, but may be usedwith bowls that are not self draining.

In treating oils with acid (usually concentrated sulfuric acid) thereare always two resultants namely: oil having a specific .gravity between.'7 and 1.0 and sludge having specific gravity between 1.10 and 1,40.Frequently there is a third resultant; namely: Aresidual acid having aspecific gravity of 1.6 or higher.

When separation is carried on in a centrifugal bowl having two outletsadjusted for oil and sludge, any separated residual acid .collectsaround the inside of the bowl shell until .it shuts off the sludgeoutlet. If, on .the other hand, .the outlets are adjusted for oil andacid, there is danger that all of the sludge will escape and permit oilto fiow from the sludge 4outlet.

I know that it is old to provide, in the bowl shell, leakage holes forthe escape of any freeacid that may collect. Because of the highpressure (500 lbs. .per sq. inch .and upwards) vat this point the holesmust be so very small that they are 'sometimes completely closed by dirtand sludge. At other times they may be corroded and eaten by acid andenlarged to such an extent that a large quantity -of `sludge can escapethrough them. Either of 'these can put a bowl out of commission.

I also know that it is old to provide ,bowls having orices throughtheshell with removabletrenewable or exchangeable nozzles screwed in fromthe outside against a gasket of defor m (Cl. 23a- 47) able material,like lead, but centrifugal force tends to 'throwsuch nozzlesV away fromthe seat `or gasket, and.v when corrosive materials are being handledthe thread may be eaten away and weakened until it will not hold thenozzle.

I alsouknowthat it is old to provide nozzles each 'having a flange'larger than the 'threaded part, the nozzle being screwed into a bowlwall from the 'inside with the flange against a seat or a Igasket sothat centrifugal force tends to forcev it tighter in place, the flange,instead of the threads, taking all stresses due to eithercentrifugalforce or hydraulic pressure; but such devices previously madecan be removed, adjusted or exchanged only while the bowl isdisassembled. p V

In4 the accompanying drawing, which illustrates -ernbodiments of. myinvention:

Y Figure 1 is a vertical section a little one side `of 'the center of acomplete .bowl showing` the preferred form of my. invention.

Figure 2 'is Aa bottom view of the same.

FigureiB` is a partial vertical rsection showing an alternative form.

'Figure 4 is an enlarged detail in vertical section of the acid outlet.

Figures 5, 6, 7 and 8 are views, similar toFig. 4, of alternativeconstructions.

a is .the shell of a bowl having a top `b and containing .a tubularshaft c, a nest of separating discs d and a top disc e. The discharge.for heavy liquid (sludge) is at f and that for light liquid (oil) is atg. At least one of these discharge openings is adjustable, in any wellknown manner, .as by anexchangeable ring which, in Fig. 1, is .shownapplied at the heavy liquid discharge. A spindle h, revolving in abearing i, supports and drives the bowl.

In the construction shown in Figures 1 and 2, two drain tubes y' startfrom k very .near to the ins-ide Vof the bowl wall and pass close to theside of the spindle h. with a downward slope to just touch the bottom ofthe bowl, at m, nearly opposite the starting point. In the construction.shown in Fig-ure 3 the tubes are horizontal and extendthrough theopposite part of the bowl. Though, for the reasons given in theaforementioned application, the tubes 7' preferably extend across thebowl, .as shown in Figures 1, 2 and 3, they may terminate near thecenter of rotation or may be still shorter and have their ends capped orplugged.

ATubes of the form shown in Figure 2 may be used at vany desired heightin hollow bowls (bowls Without separating discs).

In Figure 4 the end k of the tube y' is shown near to, but not touching,the inside of the bowl shell a. A nozzle n has a threaded portion -oscrewed into the bowl shell and made tight by a gasket p. The nozzle isrst inserted through the more distant end m of the tube j and is thenscrewed into the bowl shell. A long socket wrench, tting the squareportion q of tube 11 may be used to screw in and change nozzles. Theentrance opening r to the nozzle n is preferably smaller than theremainder of the passage.

In Figure 5 the tube or nozzle n is provided with a removable plug s inwhich the orifice r is drilled and is surrounded by a tubular cup t ofsmaller diameter than the tube 7' and having notches u in its sides atthe open end.

In the construction shown in Figure 6 the tube or nozzle n2 has, in itsouter end, a square socket l and, in its inner end, a thread Il adaptedto t a thread I2 in the plug In Figure '7 a plug v in the bowl wall mayor may not have an orice through it. This plug has a threaded portion oand a head with a flange w which makes a tight joint against a gasket p.In this modification the tube y" is short with its inner end closed by aplug :c having a square hole y to receive a tool for screwing it out. Agasket z assists in making a tight joint. Y

Figure 8 illustrates the application of the invention to a bowl whichdoes not have its bottom sloping downward toward its periphery and whichmay be an open bowl, that is, one unprovided with discs. In thisconstruction the tube j extends through one peripheralwall o the bowl a'and terminates opposite an outlet in the opposite part of the bowl wall,said outlet containing a plug v', similar to plug u of Fig. 7, or a tubeas shown in Figs. 4, 5 and 6, e. g., tube 11. of Fig. 4.

It will be noted that all devices insertable in the bowl wall arescrewed from a more central position toward a more distant position andhave a shoulder or flange that abuts against a companion surface on thebowl shell and so relieves the thread of all stresses except that of theinitial tightening.

Before operation the openings f and g are adjusted for the relativespecic gravities of the sludge and oil as instructed in Snyder PatentNo. 1,283,343 to bring the inner side of the sludge zone at the desiredlocation. By similar calculations there is determined the location forthe oriiice 1` required to cause the inner wall of the heaviest acidlikely to be collected in the bowl to be at the same or a slightlygreater radius than 7c, which should always be greater than the radiusof the bottom of the top disc e, and nozzles n of the correct length areinserted.

In operation the acid-treated oil, with the sludge formed in it, is fedinto the bowl, where the oil and sludge are separated. The oil passes upnear the center of the bowl and escapes at g. The sludge is throwntoward the outside of the bowl, passes around the bottom edge of the topdisc e and escapes at f. If there is any free acid it collects againstthe bowl wall until it covers and is forced into the end 7c of the tubej down which it passes to the orifice r and escapes through the nozzle n(or n' or n2). If there is no free acid, some sludge will escape at theacid outlet, but its viscosity is high and, because the orifice 1* isrelatively near the center of rotation, the pressure is low and thequantity is very small; and hence exact adjustment of the orifice r isnot required.

Because the location of the orice T is set to keep the inside radius ofthe acid wall always greater than the radius of the bottom of the topdisc e, the flow of sludge around that bottorn will always be the sameas if no acid were present.

With the construction shown in Figure 5 with the cup t fitting withsmall clearance around the tube n', the quantity of sludge to be forcedout before ilow of acid can begin is so small that there will be littledelay in discharge of acid` By changing the plug s it is possible Atohave the smallest size orice r that will permit proper iiow of acid orsludge.

At the end of a days run it is desirable that all acid and sludge beremoved from the bowl. With the constructions shown in Figures 4 and 5,the nozzle n (or n) may be unscrewed or removed by means of a toolinserted from the opposite end of the tube y'. With the constructionshown in Figure 6 a square plug may be inserted in the socket I0 and thetube n2 unscrewed from 'the bowl shell. Inward pressure will move thetube until the thread Il engages the thread l2, which holds the tube n2away from the hole in the bowl. With the construction shown in Figure 7removal of the plug will permit the insertion of a tool by means ofwhich the plug v can be taken out. With the construction shown in Figure8, a tool may be readily inserted through tube :i and the plug vremoved. In any of these cases the opening is effected withoutdisassembling the bowl, and on starting Vthe machine all acid, sludgeand any other matter contained in the bowl will be thrown out. n

It will be understood that one of the objects of the invention, namely,the cleaning out of the bowl after the conclusion of the centrifugalseparating or purifying action, is not dependent 'upon the use of thebowl for separating three, or even two, constituents of differentspecific gravi-y ties, or upon the provision of three, or even two,outlets for separated liquid, during the puriication operation. Thus if,for example, the construction of Figure 7 or Figure 8 should be used andthe plug in the bowl wall should not be provided with an outlet, thebowl, if used to separate sludge and oil, will not operate as describedto maintain the desired relation between these separated constituents.The principal object secured by constructions like that of Figure 7 and8 is to provide an outlet controlling device which will not functionduring the regular separation or purification process except to maintainthe outlet as absolutely closed as if the bowl wall were solid, butwhich, at the conclusion of the separating or purifying process, may beremoved without disassembly of the bowl so as to enable the bowl to beushed out and thereby thoroughly cleared of all solid or semi-solidmatter that has collected on the bowl wall. The constructions of Figures4, 5 and 6 may also be modified in like manner, that is, by closing therestricted acid escape outlet, and when so modied will still accomplishthe object of the invention last described. It should also be statedthat the threading of the plug or nozzle into the bowl wall, whilepreferred, is not absolutely essential, since the plug or nozzle and theorice in the bowl wall may have a smooth t; leakage around the plug ornozzle, during the regular centrifugal operation, being yaofiaseiao 3prevented by the pressure of the liquid holding the head of the plug ornozzle firmly on its seat.

The most eiiicient operation of the bowl requires the use of the discsd, but successful operation is not dependent on the use of discs. Thebowl may be of the open type.

In a bowl embodying my invention in its preferred and complete form,rcontinuous separation of sludge and oil may be carried on withoutdanger of interference by collection in the bowl of free acidincidentally separated from the oil and sludge; there will be smallcontamination of acid with sludge; corrosion and erosion of the acidescape orice will cause a minimum change in operation; all mattercontained therein may be discharged without disassembling; and the loadson the removable members due to centrifugal force and hydraulic pressuredo not come on screw threads.

Attention is called to the fact that though none of the dischargepassages, except that shown in Figure 8, are truly radial, the axes ofall of them diverge from a vertical radial plane by only the small anglerequired to permit them to pass at one side of the spindle h, and theydiverge from a horizontal plane by only the small angle required topermit them to pass under the bottom of the bowl, as shown in Figure 1and Figure 2. Where in the claims the words approximately radial occurthey are intended toy include all positions from truly radial to thepositions, nearly but somewhat divergent from radial, shown in thedrawing.

What I claim and desire to protect by Letters Patent is:

l. In a centrifugal bowl, the combination with a disc having a centralopening for lighter separated liquid and a bowl top having a largercentral opening for heavier separated liquid, of a discharge for stillheavier liquid comprising a tube leading from close to the bowl wallinward beyond the periphery of the zone dened by said central opening inthe bowl top, and a` nozzle whose admission end is within said tube andoutside the periphery of said zone and which terminates outside thebowl.

2. A centrifugal bowl provided with an outlet in its peripheral wall, aplug sealing said outlet and removable from the inside of the bowl andadapted to be held in liquid tight relation with the the bowl duringcentrifugation by the pressure of the liquid therein, and a tube one endof which opens into the interior of the bowl opposite'said plug andwhich extends through the bowl wall and through which a tool may beinserted to effect the removal of the plug.

3. In a centrifugal bowl having a liquid outlet concentric with the bowlaxis, the combination, with the bowl shell, of a tube whose admissionend is close to the inside of the peripheral part of the bowl wall andwhich extends therefrom inward beyond the periphery of a zone having aradius less than that of the liquid outlet, there being a hole in thebowl wall in line with the admission end of said tube, and an outletcontrol device insertable by an approximately radially outward movementinto said hole through said tube.

4. In a centrifugal bowl, the combination with a top disc having acentral opening for lighter separated liquid and a bowl topl having alarger central opening for heavier separted liquid, of means providing adischarge for still heavier separated liquid, comprising anapproximately radial passage leading, from a point, within theseparating chamber .of the bowl, nearer the bowl wall than the radiusofl the top disc, toward the bowl axis, and a second passage smallerthan and substantially coaxial lwith the rs't named passage andcommunicating at its inner end with the first named passage and insealed relation at its outer end with an escape opening in the periph-.eral part of the bowl wall.

5. In a centrifugal bowl provided with outlets for .a lighter separatedliquid and a heavier separated liquid, means, providing a discharge forstill heavier separated liquid, comprising an approximately radialpassage leading from a point, within the separating chamber of the bowl,near the peripheral part of the bowl wall toward the bowly axis and asecond passage smaller than and substantially coaxial with the firstnamed passage and communicating at its inner end with the rst namedpassage and in sealed relation at its outer end with an escape openingin the peripheral part of the vbowl wall, said means comprising alsomeans to adjustably vary the length of that part of the passage leadingfrom the peripheral part of the bowl toward the bowl axis.

6. In a centrifugal bowl provided with outlets for a lighter separatedliquid and a heavier separated liquid, a tube leading from andcommunicating with the peripheral portion of the bowl interior andextending inward beyond the bowl axis, and a removable nozzle positionedwithin the entrance end of the tube and having a substantial portion ofits length surrounded thereby and leading to the outside of the bowlthrough a point in the bowl wall adjacent to the entrance end of saidtube.

7. In a centrifugal bowl having an outlet in the peripheral part of thebowl wall, an outlet controlling device having a smaller diameter prtionpositioned in said outlet and a part of larger diameter at approximatelythe inner face of the bowl wall, combined with means, including anopening, aligning with said outlet, in a part of the bowl wall spacedfrom its periphery, and a tool-engageable element carried by said partof larger diameter, whereby said device can be removed and replacedwhile the bowl is assembled.

8. In a centrifugal bowl having an outlet in the peripheral part of thebowl wall, an outlet controlling device having a smaller diameterportion positioned in said outlet and a part of larger diameter atapproximately the inner face of the bowl wall, combined with means,including a tool-engageable element carried by said part of largerdiameter and an opening in the bowl bottom opposite said outlet andthrough which a tool is insertable to engage said element, whereby saiddevice can be removed and replaced while the bowl is assembled.

9. A centrifugal bowl provided with an outlet in its peripheral wall,and a seat adjacent the inner end of said outlet and facing toward theinterior of the bowl, a device controlling the flow through said outletand removable from the inside of the bowl and having a flange engagingsaid seat and thereby adapted to be held in liquid tight relation withthe bowl during centrifugation by the pressure of the liquid therein,and a tube one end of which opens into the interior of the bowl oppositesaid device and which extends through the bowl wall and through which atool may be inserted to effect the removal of said device.

10. In a centrifugal bowl provided with outlets for a lighter separatedliquid and a heavier separated liquid, means, providing a discharge forstill heavier Separated liquid, comprising an approximately radialpassage leading from a point, Within the separating chamber of the bowl,near the peripheral part of the bowl Wall toward the bowl axis, and asecond passage smaller than and substantially coaxial With the firstnamed passage and communicating at its inner end through a restrictedorifice, of substantially smaller diameter than the second namedpassage, with the first named passage and in sealed relation at itsouter end with an escape opening in the peripheral part of the bowlwall.

1l. In a centrifugal bowl provided with outlets for a lighter separatedliquid and a heavier separated liquid, means affording an outlet forstill heavier separated liquid, said means providing an annular passagehaving an entrance opening in the interior of the bowl close to itsperipheral wall and extending thence inward in an approximately radialdirection to a restricted oriice central of said passage and nearer tothe axis of rotation than the entrance to said passage, and a centralpassage of substantially greater diameter than said orifice extendingfrom said orice toward and thence through the peripheral wall of thebowl.

12. In a centrifugal bowl provided with outlets for a lighter separatedliquid and a heavier separated liquid, means aording a discharge forstill heavier separated liquid to the outside of the bowl, said meansproviding a passage of restricted volumeV having an inlet mouth insidethe bowl near its peripheral Wall and extending toward the bowl centerto a restricted orice withinV and surrounded by said passage, and apassage of smaller diameter than the rst passage but of substantiallygreater diameter than said orifice leading from said orice to theoutside of the peripheral bowl Wall.

13. In a centrifugal bowl provided with outlets for a lighter separatedliquid and a heavier separated liquid, means aording a discharge forstill heavier separated liquid to the outside of the bowl, said meansproviding a passage of restricted volume having an inlet mouth insidethe separating chamber of the bowl near its peripheral wall andextending thence toward and beyond a point nearer the axis of the bowl,and an outlet conduit within and surrounded by said passage and having arestricted inlet orifice of substantially le'ss diameter than saidoutlet conduit located at said point and thence extending toward andthrough the peripheral wall of the bowl.

GEORGE J. STREZYNSKI.

